1. Field of the Invention
The present invention relates generally to the orthopedic surgical arts, and more specifically to methods and apparatus for repairing a tear in a knee meniscus.
2. Description of the Prior Art
The term "meniscus" describes a fibrous cartilage located within human joints which functions to absorb shock and prevent friction during joint movement. There are two generally crescent-shaped meniscus on opposite sides of the human knee. Frequently, a tear develops in one of the knee meniscus, causing pain and discomfort. Unless treated, a torn knee meniscus may frequently deteriorate, causing additional complications.
In treating a torn knee meniscus, open meniscectomy was previously a common orthopedic procedure. In 1948, the degenerative characteristics of a total meniscectomy were reported; nevertheless, the use of total meniscectomy continued for many years, for want of a better procedure. See Fairbank, "Knee Joint Changes After Meniscectomy", Journal of Bone and Joint Surgery, 30-B (4): pp. 664-670 (1948). Partial meniscectomy proved to be effective; however, there was continued evidence that the destructive changes noted by Fairbank may also accompany a partial meniscectomy.
Recently, researchers have begun directing efforts at meniscal preservation via primary surgical repair, using arthroscopy. Scott et al, "Combined Posterior Incision and Arthroscopic Intra-articular Repair"; Journal of Bone and Joint Surgery, 68-A: pp. 847-861 (1986). The surgical repair technique requires the passage of sutures and surgical needles through the knee capsule, which are tied externally. See Scott et al, supra, and DeHaven, "Peripheral Meniscus Repair: An Alternative to Meniscectomy", Orthop. Trans. 5:399-400 (1981). There are a number of drawbacks to this procedure, including the need for an accessory incision in the back of the knee, potential injury to the nerves and blood vessels by passing the needle through the knee, as well as the additional time and advanced skills required.
There are a number of stapling instruments disclosed in the prior art which are useful for orthopedic purposes. For example, in U.S. Pat. No. 4,580,563, Gross discloses an arthroscopic stapling instrument for repairing capsular disruptions associated with shoulder dislocations and subluxations.